We are collaborating in a study to evaluate protein production in the exocrine rate submandibular gland during aging. We are evaluating ultrastructural features of the organelles involved in protein synthesis and processing in enzymatically dispersed cell preparations from young adult and aged male rats. Our colleagues at NIDR are measuring levels of protein production in these cells using radioisotopic methods and evaluating the nature of new protein synthesis by employing gel electrophoresis and autofluorography. Results demonstrate a diminution in protein production by cells from aged rats, in addition to some lteration in specific protein processing by old rat cells.